According to Europa, in the EU ships are fast becoming the biggest source of air pollution. Unless more action is taken they are set to emit more than all land sources combined by 2020.
A 2003 study found that large ships generate 30 percent of global nitrogen emissions and 16 percent of sulfur emissions from all petroleum sources. Despite the fact that ships are more energy efficient than other forms of commercial transportation, marine engines operate on extremely dirty fuels. Most large ships use the dirtiest and least expensive diesel available, bunker oil.
Shipping is a small contributor to the world total CO2 emissions (1.8% of world total CO2 emissions in 1996)
According to a Reuters story, a group of north European companies plan to install a fuel-cell aboard a supply ship in 2008 and believe that a large share of the marine world will follow suit within 25 years. Norwegian shipping group Eidesvik Offshofre ASA plans to install a 330 kW fuel cell system on an oilfield supply vessel next year.
It is estimated that fuel cells now cost about six times more than diesel generators. But the technology can be up to 50 percent more efficient and much cleaner,
When powered by liquefied natural gas (LNG), as the first full-scale test model will be, carbon dioxide emissions are cut in half compared to diesel engines running on marine bunker fuel and sulphur and nitrogen oxide exhausts are nearly eliminated.
Iceland plans to convert its entire fishing fleet to hydrogen fuel cells as part of its environmental drive.
The shipping industry says it is more green than other modes of transport considering the huge amount of trade that ships carry, although the heavy fuel used in shipping emits 700 times more sulphur dioxide than diesel exhausts from road vehicles.
The Reuters story fails to point out that the reductions in emissions is largely brought about by using LNG rather than Bunker C, as well as the greater efficiency of the fuel cells.